Semiconductor technology for VLSI: Plasma etching and high pressure oxidation

The large scale integration of electronic circuits on silicon requires etching of structures in the range of 1 micrometer or smaller. This cannot be achieved by wet chemical means. Dry etching processes, however, do produce an exact replica of the desired structure in those materials which are common in silicon planar technology. These procedures depend on the RF-energy, on how this is coupled to the substrate to be etched, and on the pressure. They are, accordingly, called plasma etching or reactive ion etching. Their etch rate and selectivity of the relevant materials for various gases was examined. MOS properties can be restored to their original level by annealing. The design of a practical etch reactor is outlined.